A conventional blood purification apparatus that performs blood purification treatment using container bags in which dialysate, substitution fluid, and the like are contained (a dialysate bag and a substitution fluid bag) includes a hanger portion having hook portions to which the container bags can be attached, and a measuring device (load meter) capable of measuring the weights of the container bags held by the hanger portion. For example, by a peristaltic pump, dialysate is supplied from a container bag in which dialysate is contained (container bag for dialysate) to a blood purifier (dialyzer) at a predetermined flow rate, and drainage from the blood purifier is caused to be contained in another container bag (container bag for drainage) at a predetermined flow rate. For example, by another peristaltic pump, substitution fluid can also be supplied from a container bag in which substitution fluid is contained (container bag for substitution fluid) to a blood circuit at a predetermined flow rate.
In the above conventional blood purification apparatus, when in the middle of blood purification treatment, the dialysate in the container bag for dialysate or the substitution fluid in the container bag for substitution fluid is consumed and the container bag becomes empty, or the container bag for drainage is filled with drainage, the container bag needs to be appropriately replaced by a worker. When replacing the container bag, by the operation of the worker, the control relating to the blood purification treatment such as supply of dialysate and substitution fluid, the measurement by the measuring device, and the like are temporarily stopped, and the desired container bag is replaced in the temporarily stopped state, and then the control relating to the blood purification treatment is resumed. Because such a prior art is not related to inventions publicly known through literature, there is no information on prior art literature to be described.